Preeclampsia acts differently in in vitro fertilization versus spontaneous twins

To investigate risk factors and pregnancy outcome of spontaneous vs in-vitro fertilization (IVF) twins complicated with preeclampsia. A retrospective population-based cohort study comparing maternal and neonatal outcome in IVF vs spontaneously conceived twins was conducted. Deliveries occurred in a tertiary medical center between the years 1988 and 2010. Women who conceived after ovulation induction and those with chronic hypertension were excluded from the study. Multiple logistic regression models were used to control for confounders. The study population included 4428 twin pregnancies, of these 314 (7.1%) had preeclampsia; 64 (20.3%) were IVF twins and 250 (79.7%) were spontaneous twins. Preeclampsia was more common in IVF compare to spontaneous twins (13.8 vs 7.6%, OR = 1.81, CI = 1.50-2.17, P < 0.001). The mothers of IVF twins were significantly older, and were more likely to be nulliparous. The rate of cesarean delivery was higher among IVF twins. The mean gestational age at delivery and the mean birth weight were significantly lower in IVF twins. While controlling for confounders using a multivariate analysis, IVF was found as an independent risk factor for preterm delivery in twin pregnancies with preeclampsia. However, there was no difference in the perinatal mortality or 5 min Apgar scores < 7 between the two groups. Preeclampsia is more common in IVF twins compared to spontaneous twin pregnancies. IVF twins with preeclampsia are at an increased risk for cesarean delivery, preterm delivery and low birth weight.